Synthesis, crystal structures, and thermal and spectroscopic properties of two Cd(II) metal-organic frameworks with a versatile ligand

2016 ◽  
Vol 71 (8) ◽  
pp. 909-917 ◽  
Author(s):  
Jia-Ming Li ◽  
Kun-Huan He ◽  
Zhong-Feng Shi ◽  
Hui-Yuan Gao ◽  
Yi-Min Jiang

AbstractTwo new metal-organic frameworks, namely, [Cd(L)(H2O)]n (1) and {[Cd0.5(L)(4,4′-bipy)0.5][Cd0.5(H2O)(4,4′-bipy)0.5]·H2O}n (2), where H2L = N-pyrazinesulfonyl-glycine and 4,4′-bipy = 4,4′-bipyridine, have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental, thermogravimetric, and photoluminescent analysis. X-ray diffraction crystallographic analyses indicate that 1 displays a distorted octahedral metal coordination in a 3-connected (4, 82) topology, while the molecular structure of 2 has a 4-connected (4, 4) topology with two perfectly octahedrally coordinated Cd centers. The L2– ligand serves as a N,N,O-tridentate, μ2-pyrazine-bridging, and μ2-carboxylate-bridging ligand in 1, and as a N,O-bidentate and μ2-carboxylate-bridging ligand in 2. In the crystal, a 3D supramolecular architecture is formed by O–H···O hydrogen bond interactions in 1, but through O–H···O as well as π···π stacking in 2. The two compounds show intense fluorescence in the solid state at room temperature.

2017 ◽  
Vol 727 ◽  
pp. 628-634
Author(s):  
Ying Jie Zhang ◽  
Li Xian Sun ◽  
Fen Xu

A novel zinc metal organic frameworks, named ZnL(2,2′-bpy), has been successfully synthesized, serving 3,6-dicarboxylic-9-ethylcarbazole acid (H2L) as ligand. This kind of ZnMOFs was characterized by FI-IR, elemental analysis, SEM, powder X-ray diffraction and single crystal X-ray diffraction to illustrate the structures. TG analysis was applied to investigate the thermostability. Structural analysis demonstrates that ZnMOFs possess triclinic crystal structure which is a 1D chain that occurs distorted-octahedral coordination geometry. Furthermore, the luminescent performance of ZnMOFs is performed and discussed in detail. The results show that ZnMOFs can emit blue luminescence originating, which is assigned to the ligand-to-metal charge transfer (LMCT).


2016 ◽  
Vol 71 (11) ◽  
pp. 1169-1175
Author(s):  
Jia-Ming Li ◽  
Kun-Huan He ◽  
Zhong-Feng Shi ◽  
Hui-Yuan Gao ◽  
Yi-Min Jiang

AbstractTwo new metal–organic frameworks, namely, [Ag2(L)]n (1) and {[Ag2.5(L)(bpy)2]·(NO3)0.5·(H2O)4.5}n (2), where H2L=N-pyrazinesulfonyl-glycine and bpy=4,4′-bipyridine, have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental analysis. X-ray diffraction crystallographic analyses indicate that 1 displays a silver carboxylate-sulfonamide layer structure containing an uncommon heptanuclear [Ag7] cluster wherein four silver(I) atoms form an Ag4 plane with in a three-connected (6, 3) net. The molecular structure of 2 has three crystallographically independent two-coordinate Ag centers with an intersecting Ag-bpy chain structure in a six-connected (3, 6) or a four-connected (4, 4) topology. The L2− ligand serves as a μ7-(η2-O,N), (η2-O′,N′), O,O″,O″′,N,N″ ligand in 1 and as a μ3-(η2-O,N), N,O′ ligand in 2. In the crystal, a 3D supramolecular architecture is formed by coordinative bonding in 1, but through O–H···O bonding as well as π···π stacking in 2. The two compounds show a combination of coordinative bonds, ligand-supported Ag···Ag interactions and weak Ag···O/N coordinative interactions in the solid state.


2020 ◽  
Vol 75 (8) ◽  
pp. 727-732
Author(s):  
Chen Zhang ◽  
Jian-Qing Tao

AbstractA new Cu(II) metal-organic framework, [Cu(L)(OBA)·H2O]n (1) [H2OBA = 4,4′-oxybis(benzoic acid), L = 3,5-di(1H-benzimidazol-1-yl)pyridine] was hydrothermally synthesized and characterized through IR spectroscopy, elemental and thermal analysis and single-crystal X-ray diffraction. Complex 1 is a four-connected uni-nodal 2D net with a (44·62) topology which shows an emission centered at λ ∼393 nm upon excitation at λ = 245 nm. Moreover, complex 1 possesses high photocatalytic activities for the decomposition of Rhodamine B (RhB) under UV light irradiation.


Author(s):  
Stephen J. I. Shearan ◽  
Jannick Jacobsen ◽  
Ferdinando Costantino ◽  
Roberto D’Amato ◽  
Dmitri Novikov ◽  
...  

2021 ◽  
Author(s):  
Qing-Xia Yao ◽  
Miaomiao Tian ◽  
Jun Zheng ◽  
Jintang Xue ◽  
Xuze Pan ◽  
...  

A series of microporous Ln(III)-based metal-organic frameworks (1-Ln) have been hydrothermally synthesized by using 4,4',4''-nitrilotribenzoic acid (H3NTB). Single crystal X-ray diffraction analyses show 1-Ln are isostructural and have 3D porous...


2014 ◽  
Vol 70 (a1) ◽  
pp. C157-C157
Author(s):  
Claire Hobday ◽  
Stephen Moggach ◽  
Carole Morrison ◽  
Tina Duren ◽  
Ross Forgan

Metal-organic frameworks (MOFs) are a well-studied class of porous materials with the potential to be used in many applications such as gas storage and catalysis.[1] UiO-67 (UiO = University of Oslo), a MOF built from zirconium oxide units connected with 4,4-biphenyldicarboxylate (BDC) linkers, forms a face centred cubic structure. Zirconium has a high affinity towards oxygen ligands making these bridges very strong, resulting in UiO-based MOFs having high chemical and thermal stability compared to other MOF structures. Moreover, UiO-67 has become popular in engineering studies due to its high mechanical stability.[2] Using high pressure x-ray crystallography we can exert MOFs to GPa pressures, experimentally exploring the mechanical stability of MOFs to external pressure. By immersing the crystal in a hydrostatic medium, pressure is applied evenly to the crystal. On surrounding a porous MOF with a hydrostatic medium composed of small molecules (e.g. methanol), the medium can penetrate the MOF, resulting in medium-dependant compression. On compressing MOF-5 (Zn4O(BDC)3) using diethylformamide as a penetrating medium, the framework was shown to have an increased resistance to compression, becoming amorphous several orders of magnitude higher in pressure than observed on grinding the sample.[3] Here we present a high-pressure x-ray diffraction study on the UiO-based MOF UiO-67, and several new synthesised derivatives built from same metal node but with altered organic linkers, allowing us to study in a systematic way, the mechanical stability of the MOF, and its pressure dependence on both the linker, and pressure medium.


2021 ◽  
Vol 9 ◽  
Author(s):  
Wang Xie ◽  
Jie Wu ◽  
Xiaochun Hang ◽  
Honghai Zhang ◽  
Kang shen ◽  
...  

By employment of amino-functionalized dicarboxylate ligands to react with d10 metal ions, four novel metal-organic frameworks (MOFs) were obtained with the formula of {[Cd(BCPAB)(μ2-H2O)]}n (1), {[Cd(BDAB)]∙2H2O∙DMF}n (2), {[Zn(BDAB)(BPD)0.5(H2O)]∙2H2O}n (3) and {[Zn(BDAB)(DBPB)0.5(H2O)]∙2H2O}n (4) (H2BCPAB = 2,5-bis(p-carbonylphenyl)-1-aminobenzene; H2BDAB = 1,2-diamino-3,6-bis(4-carboxyphenyl)benzene); BPD = (4,4′-bipyridine); DBPB = (E,E-2,5-dimethoxy-1,4-bis-[2-pyridin-vinyl]-benzene; DMF = N,N-dimethylformamide). Complex 1 is a three-dimensional (3D) framework bearing seh-3,5-Pbca nets with point symbol of {4.62}{4.67.82}. Complex 2 exhibits a 4,4-connected new topology that has never been reported before with point symbol of {42.84}. Complex 3 and 4 are quite similar in structure and both have 3D supramolecular frameworks formed by 6-fold and 8-fold interpenetrated 2D coordination layers. The structures of these complexes were characterized by single crystal X-ray diffraction (SC-XRD), thermal gravimetric analysis (TGA) and powder X-ray diffraction (PXRD) measurements. In addition, the fluorescence properties and the sensing capability of 2–4 were investigated as well and the results indicated that complex 2 could function as sensor for Cu2+ and complex 3 could detect Cu2+ and Ag+via quenching effect.


2020 ◽  
Author(s):  
Stephen Shearan ◽  
Jannick Jacobsen ◽  
Ferdinando Costantino ◽  
Roberto D’Amato ◽  
Dmitri Novikov ◽  
...  

We report on the results of a thorough <i>in situ</i> synchrotron powder X-ray diffraction study of the crystallisation in aqueous medium of two recently discovered perfluorinated Ce(IV)-based metal-organic frameworks (MOFs), analogues of the already well investigated Zr(IV)-based UiO-66 and MIL-140A, namely, F4_UiO-66(Ce) and F4_MIL-140A(Ce). The two MOFs were originally obtained in pure form in similar conditions, using ammonium cerium nitrate and tetrafluoroterephthalic acid as building blocks, and small variations of the reaction parameters were found to yield mixed phases. Here, we investigate the crystallisation of these compounds <i>in situ</i> in a wide range of conditions, varying parameters such as temperature, amount of the protonation modulator nitric acid (HNO<sub>3</sub>) and amount of the coordination modulator acetic acid (AcOH). When only HNO<sub>3</sub> is present in the reaction environment, F4_MIL-140A(Ce) is obtained as a pure phase. Heating preferentially accelerates nucleation, which becomes rate determining below 57 °C, whereas the modulator influences nucleation and crystal growth to a similar extent. Upon addition of AcOH to the system, alongside HNO<sub>3</sub>, mixed-phased products, consisting of F4_MIL-140A(Ce) and F4_UiO-66(Ce), are obtained. In these conditions, F4_UiO-66(Ce) is always formed faster and no interconversion between the two phases occurs. In the case of F4_UiO-66(Ce), crystal growth is always the rate determining step. An increase in the amount of HNO<sub>3</sub> slows down both nucleation and growth rates for F4_MIL-140A(Ce), whereas nucleation is mainly affected for F4_UiO-66(Ce). In addition, a higher amount HNO<sub>3</sub> favours the formation of F4_MIL-140A(Ce). Similarly, increasing the amount of AcOH leads to slowing down of the nucleation and growth rate, but favours the formation of F4_UiO-66(Ce). The pure F4_UiO-66(Ce) phase could also be obtained when using larger amounts of AcOH in the presence of minimal HNO<sub>3</sub>. Based on these <i>in situ</i> results, a new optimised route to achieving a pure, high quality F4_MIL-140A(Ce) phase in mild conditions (60 °C, 1 h) is also identified.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Duc V. Dinh ◽  
Nan Hu ◽  
Yoshio Honda ◽  
Hiroshi Amano ◽  
Markus Pristovsek

Abstract Growth of AlxGa1−xN layers (0 ≤ x ≤ 1) simultaneously on polar (0001), semipolar ($$10\bar{{\rm{1}}}$$ 10 1 ¯ 3) and ($$11\bar{{\rm{2}}}2$$ 11 2 ¯ 2 ), as well as nonpolar ($$10\bar{{\rm{1}}}0$$ 10 1 ¯ 0 ) and ($$11\bar{{\rm{2}}}0$$ 11 2 ¯ 0 ) AlN templates, which were grown on planar sapphire substrates, has been investigated by metal-organic vapour phase epitaxy. By taking into account anisotropic in-plane strain of semi- and non-polar layers, their aluminium incorporation has been determined by x-ray diffraction analysis. Optical emission energy of the layers was obtained from room-temperature photoluminescence spectra, and their effective bandgap energy was estimated from room-temperature pseudo-dielectric functions. Both x-ray diffraction and optical data consistently show that aluminium incorporation is comparable on the polar, semi- and non-polar planes.


2011 ◽  
Vol 339 ◽  
pp. 313-316
Author(s):  
Xiu Mei Li ◽  
Zhi Tao Wang ◽  
Qing Wei Wang

A new metal-organic complex Cd2(cbba)4(phen)2 (Hcbba = 2-(4΄-chlorine-benzoyl)- benzoic acid, phen = 1,10-phenanthroline) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, fluorescence spectrum and single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space group Pbcn with a = 12.0976(4), b = 18.0925(6), c = 31.6829(10) Å, V = 6934.6(4) Å3, C80H48Cd2Cl4N4O12, Mr = 1623.82, Dc = 1.555 g/cm3, μ(MoKα) = 0.8365 mm1, F(000) = 3264, Z = 4, the final R = 0.0396 and wR = 0.0960 for 5372 observed reflections (I > 2(I)). It exhibits a 3D supramolecular network through π-π interactions and shows green luminescent property at room temperature.


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